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Keys to good fracturing — 6. New fluids help increase effectiveness of hydraulic fracturing
301A 896O97 Engineering properties of Cochin marine clays and its stabilisation with lime Jose, B T; Sridharan, A; Abraham, B M Proc Ninth Sontbeast Asian Geoteclmieal Conference, Bangkok, 7-11 December 1987 I/1, P5.115-5.126. Publ Bangkok: Southeast Asian Geotechnical Society, 1987 Cochin marine clays have high liquid limits, water content close to the limits, high compressibility and poor shear strength. Properties of moist and oven dried samples are compared, showing that drying affects Atterberg limits and grain size distribution, due to aggregation of the finer particles. Lime was added to improve engineering properties, and strength and compressibility tested in the laboratory. Results show that as curing time increases, liquid limit and shrinkage limit increase. Shear strength increases with lime content and curing time. Preliminary resistivity studies are presented.
896O98 Engineering properties of coastal subsoils in peninsular Malaysia Abdullah, A M L B; Chandra, S Proc Ninth Southeast Asian Geotechnical Conference, Bangkok, 7-11 December 1987 VI, P5.127-5.138. Publ Bangkok: Southeast Asian Geotechnical Society, 1987 Properties of the soft clay soils of coastal Malaysia are presented. Texture, moisture content, Atterberg limits, organic content, salt content, pH, sensitivity, compressibility and shear strength are described. The clays are silty and normally consolidated. Values for thickness, compressibility, void ratio and bulk density tend to be higher on the west coast than on the east coast.
896099 Effects of stress history on shear modulus of saturated Ottawa sand Yu, C; Tsai, C Proc Ninth Southeast Asian Geotechnical Conference, Bangkok, 7-11 December 1987 I/1, P5.139-5.146. Publ Bangkok: Southeast Asian Geotechnical Society, 1987 Cyclic triaxiai tests were undertaken on Ottawa sand to evaluate: (1) relation between shear modulus and excess porewater pressure ratio; (2) relation between shear modulus and cycle of stress history; and (3) relation between shear modulus and duration of reconsolidation time. Results show that shear modulus increases in all three cases, although when pore pressure ratio exceeds 0.133, shear modulus begins to decrease gradually.
Fracture processes 896100 Application of stereophotngrammetry to the strain localization in concrete (In French) Torrenti, J M; Desrues, J; Puch, C; Mailer, Y Bull Liaison Labs Ponts Chnussees N159, Jan-Feb 1989, P105-110 The principle of stereophotogrammetry is described and its precision studied. The method is illustrated with the problem of strain Iocalisation in concrete compression. It is shown that at stress peak localisation occurs. Continuum concepts cannot interpret tests under these conditions accurately.
896101 Keys to good fracturing - 5. Conductive fractures and staged treatments increase reservoir productivity Ebinger, C D; Hunt, E Oil Gas 1 1.'87, N21, 22 May 1989, t'64-67 Conductivity of the induced fracture is one of the least understood factors in successful hydraulic fracturing design. Laboratory and field work to examine the fractures are described, and the influence of proppant type, concentration and embedment, and fracturing fluid properties considered. The various techniques of stage fracturing for use in layered formation are briefly discussed: retrievable bridge plug and packer; perforation ball sealers; 'Pine Island' fracturing; baffle ball and collar; and limited entry.
896102 Keys to good fracturing - 6. New fluids help increase effectiveness of hydraulic fracturing Ebinger, C D; Hunt, E Oil Gas J V87, N23, 5 June 1989, P53-55 Fracturing fluids are used to initiate formation parting, extend the fractures, and to transport and distribute the proppant. The correct choice of fluid is vital for efficient fracturing. The various fluid types and areas of application are described: water based, polymer emulsion, oil based, gaseous, acid based, and slurryable polymer systems. The influence of viscosifiers and fluid rheology are also discussed.
896103 Theoretical analysis of gas drainage from virgin coal seams by the hydraulic fracturing Zhou Shining; Lin Baiquan Proc International Symposium on Modern Mining Technology, Talan, October 1988 P18-28. Pub/Taian: Shandong Institute of Mining and Technology, 1988 Drainage of methane gas from coal seams using hydraulic fracturing in vertical boreholes has been studied numerically and in the field. The quantity of gas flowing before and after fracturing is evaluated under idealised conditions. The permeability and thickness of the bands of sand proppant in the fissures are important parameters determining gas flow. Field gas flows are lower than those calculated, as the sand becomes mixed with water and coal powder during fracturing, which decreases permeability. Development of improved fracturing fluid and proppant is suggested.
896104 Investigation of poroelastic effects related to hydraulic fracture propagation in rock and stress measurement techniques Boone, T J; lngraffea, A R Rock Mockaaics as a Guide for EO~cient Utilization of Natural Resources: Proc 30th U.S. Symposium, Morgutown, 19-22 Jane 1989 P73-80. Publ Rotterdam: A A Balkema, 1989 Finite element/finite difference numerical simulations are used to study initiation and propagation of hydraulic fractures from a borehole in a poroelastic rock. Poroelastic effects are seen to have significant influence on measured principal stresses. Conclusions include: breakdown pressure is not necessarily correlated with fracture initiation; borehole pressure logs can be used to identify fracture closure times; and poroelastic effects can cause borehole pressure at fracture closure to exceed minimum in situ stress.
© 1989 Pergamon Press pie. Reproduction not permitted
896O98 Engineering properties of coastal subsoils in peninsular Malaysia Abdullah, A M L B; Chandra, S Proc Ninth Southeast Asian Geotechnical Conference, Bangkok, 7-11 December 1987 VI, P5.127-5.138. Publ Bangkok: Southeast Asian Geotechnical Society, 1987 Properties of the soft clay soils of coastal Malaysia are presented. Texture, moisture content, Atterberg limits, organic content, salt content, pH, sensitivity, compressibility and shear strength are described. The clays are silty and normally consolidated. Values for thickness, compressibility, void ratio and bulk density tend to be higher on the west coast than on the east coast.
896099 Effects of stress history on shear modulus of saturated Ottawa sand Yu, C; Tsai, C Proc Ninth Southeast Asian Geotechnical Conference, Bangkok, 7-11 December 1987 I/1, P5.139-5.146. Publ Bangkok: Southeast Asian Geotechnical Society, 1987 Cyclic triaxiai tests were undertaken on Ottawa sand to evaluate: (1) relation between shear modulus and excess porewater pressure ratio; (2) relation between shear modulus and cycle of stress history; and (3) relation between shear modulus and duration of reconsolidation time. Results show that shear modulus increases in all three cases, although when pore pressure ratio exceeds 0.133, shear modulus begins to decrease gradually.
Fracture processes 896100 Application of stereophotngrammetry to the strain localization in concrete (In French) Torrenti, J M; Desrues, J; Puch, C; Mailer, Y Bull Liaison Labs Ponts Chnussees N159, Jan-Feb 1989, P105-110 The principle of stereophotogrammetry is described and its precision studied. The method is illustrated with the problem of strain Iocalisation in concrete compression. It is shown that at stress peak localisation occurs. Continuum concepts cannot interpret tests under these conditions accurately.
896101 Keys to good fracturing - 5. Conductive fractures and staged treatments increase reservoir productivity Ebinger, C D; Hunt, E Oil Gas 1 1.'87, N21, 22 May 1989, t'64-67 Conductivity of the induced fracture is one of the least understood factors in successful hydraulic fracturing design. Laboratory and field work to examine the fractures are described, and the influence of proppant type, concentration and embedment, and fracturing fluid properties considered. The various techniques of stage fracturing for use in layered formation are briefly discussed: retrievable bridge plug and packer; perforation ball sealers; 'Pine Island' fracturing; baffle ball and collar; and limited entry.
896102 Keys to good fracturing - 6. New fluids help increase effectiveness of hydraulic fracturing Ebinger, C D; Hunt, E Oil Gas J V87, N23, 5 June 1989, P53-55 Fracturing fluids are used to initiate formation parting, extend the fractures, and to transport and distribute the proppant. The correct choice of fluid is vital for efficient fracturing. The various fluid types and areas of application are described: water based, polymer emulsion, oil based, gaseous, acid based, and slurryable polymer systems. The influence of viscosifiers and fluid rheology are also discussed.
896103 Theoretical analysis of gas drainage from virgin coal seams by the hydraulic fracturing Zhou Shining; Lin Baiquan Proc International Symposium on Modern Mining Technology, Talan, October 1988 P18-28. Pub/Taian: Shandong Institute of Mining and Technology, 1988 Drainage of methane gas from coal seams using hydraulic fracturing in vertical boreholes has been studied numerically and in the field. The quantity of gas flowing before and after fracturing is evaluated under idealised conditions. The permeability and thickness of the bands of sand proppant in the fissures are important parameters determining gas flow. Field gas flows are lower than those calculated, as the sand becomes mixed with water and coal powder during fracturing, which decreases permeability. Development of improved fracturing fluid and proppant is suggested.
896104 Investigation of poroelastic effects related to hydraulic fracture propagation in rock and stress measurement techniques Boone, T J; lngraffea, A R Rock Mockaaics as a Guide for EO~cient Utilization of Natural Resources: Proc 30th U.S. Symposium, Morgutown, 19-22 Jane 1989 P73-80. Publ Rotterdam: A A Balkema, 1989 Finite element/finite difference numerical simulations are used to study initiation and propagation of hydraulic fractures from a borehole in a poroelastic rock. Poroelastic effects are seen to have significant influence on measured principal stresses. Conclusions include: breakdown pressure is not necessarily correlated with fracture initiation; borehole pressure logs can be used to identify fracture closure times; and poroelastic effects can cause borehole pressure at fracture closure to exceed minimum in situ stress.
© 1989 Pergamon Press pie. Reproduction not permitted